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Posted to dev@jclouds.apache.org by Zack Shoylev <za...@RACKSPACE.COM> on 2013/06/13 06:10:02 UTC
lazy loading question
I have an API call that returns a list of items currently represented by a domain class. Unfortunately the list method does not return all details (you get the extra details with a separate call). When a user requests those extra details from the domain object, they might not be initialized. What is the proper way in jclouds to lazy load them? I can do a few different one-off solutions but wondering what is the consistent way to handle this problem.
What I have found similar & existing currently in code is in the openstack nova ServerApi, the list() vs listInDetail(). In this case the problem is solved by making sure the user gets the object(s) with extra details manually. In my case the API does not provide a way to get a collection with detailed info through a single call, however.
Thanks!
RE: lazy loading question
Posted by Ignasi <ig...@gmail.com>.
You can also take a look at the 'strategy' package in jclouds-chef/core.
All Chef api list methods return only the name and a few more fields of
each resource. In that package you'll find the strategies used to
concurrently fetch the details of those respurces (clients and nodes four
example).
El 13/06/2013 08:03, "Koper, Dies" <di...@fast.au.fujitsu.com> escribió:
> FWIW, for FGCP I was looking at listing nodes with few details in list
> (whatever attributes I can get from one call to the backend) and in
> listInDetail() make several calls to the backend (three or so per node?)
> to collect all the details (password, status, public IP address, etc.).
>
> In practice, as I'm using the ComputeServiceAdapter, there is no
> listInDetail method so I'm getting all details from the backend in
> getNode using several API calls, and in listNodes retrieve the list of
> node ids and call getNode for each and aggregate those results.
> I have been considering to refactor and implement separate strategy
> classes instead of using ComputeServiceAdapter.
>
> Regards,
> Dies Koper
>
>
> > -----Original Message-----
> > From: Zack Shoylev [mailto:zack.shoylev@RACKSPACE.COM]
> > Sent: Thursday, 13 June 2013 2:10 PM
> > To: dev@jclouds.incubator.apache.org
> > Subject: lazy loading question
> >
> > I have an API call that returns a list of items currently represented
> > by a domain class. Unfortunately the list method does not return all
> > details (you get the extra details with a separate call). When a user
> > requests those extra details from the domain object, they might not be
> > initialized. What is the proper way in jclouds to lazy load them? I
> can
> > do a few different one-off solutions but wondering what is the
> consistent
> > way to handle this problem.
> > What I have found similar & existing currently in code is in the
> openstack
> > nova ServerApi, the list() vs listInDetail(). In this case the problem
> > is solved by making sure the user gets the object(s) with extra
> details
> > manually. In my case the API does not provide a way to get a
> collection
> > with detailed info through a single call, however.
> > Thanks!
>
>
RE: lazy loading question
Posted by "Koper, Dies" <di...@fast.au.fujitsu.com>.
FWIW, for FGCP I was looking at listing nodes with few details in list
(whatever attributes I can get from one call to the backend) and in
listInDetail() make several calls to the backend (three or so per node?)
to collect all the details (password, status, public IP address, etc.).
In practice, as I'm using the ComputeServiceAdapter, there is no
listInDetail method so I'm getting all details from the backend in
getNode using several API calls, and in listNodes retrieve the list of
node ids and call getNode for each and aggregate those results.
I have been considering to refactor and implement separate strategy
classes instead of using ComputeServiceAdapter.
Regards,
Dies Koper
> -----Original Message-----
> From: Zack Shoylev [mailto:zack.shoylev@RACKSPACE.COM]
> Sent: Thursday, 13 June 2013 2:10 PM
> To: dev@jclouds.incubator.apache.org
> Subject: lazy loading question
>
> I have an API call that returns a list of items currently represented
> by a domain class. Unfortunately the list method does not return all
> details (you get the extra details with a separate call). When a user
> requests those extra details from the domain object, they might not be
> initialized. What is the proper way in jclouds to lazy load them? I
can
> do a few different one-off solutions but wondering what is the
consistent
> way to handle this problem.
> What I have found similar & existing currently in code is in the
openstack
> nova ServerApi, the list() vs listInDetail(). In this case the problem
> is solved by making sure the user gets the object(s) with extra
details
> manually. In my case the API does not provide a way to get a
collection
> with detailed info through a single call, however.
> Thanks!